#include <iostream>
#include <cstring>
using namespace std;

class POINT
{
private:
  double x, y;

public:
  POINT()
  {
    x = 0;
    y = 0;
  }

  POINT(double x, double y)
  {
    set(x, y);
  }

  void set(double x, double y)
  {
    this->x = x;
    this->y = y;
  }
  void show();
};

void POINT::show()
{
  cout << "x=" << x << "  y=" << y;
}

class CIRCLE : public POINT
{
private:
  double radius;

public:
  CIRCLE() : POINT() //默认构造函数
  {
    radius = 0;
  }
  CIRCLE(double x, double y, double r) : POINT(x, y) //带参数的构造函数
  {
    radius = r;
  }
  void set(double x, double y, double r)
  {
    POINT::set(x, y);
    radius = r;
  }

  void show()
  {
    POINT::show();
    cout << "r=" << radius;
  }
};
